1 //===--- CGVTables.h - Emit LLVM Code for C++ vtables -----------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This contains code dealing with C++ code generation of virtual tables. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef CLANG_CODEGEN_CGVTABLE_H 15 #define CLANG_CODEGEN_CGVTABLE_H 16 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/GlobalVariable.h" 19 #include "clang/Basic/ABI.h" 20 #include "clang/AST/BaseSubobject.h" 21 #include "clang/AST/CharUnits.h" 22 #include "clang/AST/GlobalDecl.h" 23 #include "clang/AST/VTableBuilder.h" 24 25 namespace clang { 26 class CXXRecordDecl; 27 28 namespace CodeGen { 29 class CodeGenModule; 30 31 class CodeGenVTables { 32 CodeGenModule &CGM; 33 34 VTableContext VTContext; 35 36 /// VTables - All the vtables which have been defined. 37 llvm::DenseMap<const CXXRecordDecl *, llvm::GlobalVariable *> VTables; 38 39 /// VTableAddressPointsMapTy - Address points for a single vtable. 40 typedef llvm::DenseMap<BaseSubobject, uint64_t> VTableAddressPointsMapTy; 41 42 typedef std::pair<const CXXRecordDecl *, BaseSubobject> BaseSubobjectPairTy; 43 typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t> SubVTTIndiciesMapTy; 44 45 /// SubVTTIndicies - Contains indices into the various sub-VTTs. 46 SubVTTIndiciesMapTy SubVTTIndicies; 47 48 typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t> 49 SecondaryVirtualPointerIndicesMapTy; 50 51 /// SecondaryVirtualPointerIndices - Contains the secondary virtual pointer 52 /// indices. 53 SecondaryVirtualPointerIndicesMapTy SecondaryVirtualPointerIndices; 54 55 /// EmitThunk - Emit a single thunk. 56 void EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk, 57 bool UseAvailableExternallyLinkage); 58 59 /// MaybeEmitThunkAvailableExternally - Try to emit the given thunk with 60 /// available_externally linkage to allow for inlining of thunks. 61 /// This will be done iff optimizations are enabled and the member function 62 /// doesn't contain any incomplete types. 63 void MaybeEmitThunkAvailableExternally(GlobalDecl GD, const ThunkInfo &Thunk); 64 65 /// CreateVTableInitializer - Create a vtable initializer for the given record 66 /// decl. 67 /// \param Components - The vtable components; this is really an array of 68 /// VTableComponents. 69 llvm::Constant *CreateVTableInitializer(const CXXRecordDecl *RD, 70 const VTableComponent *Components, 71 unsigned NumComponents, 72 const VTableLayout::VTableThunkTy *VTableThunks, 73 unsigned NumVTableThunks); 74 75 public: 76 CodeGenVTables(CodeGenModule &CGM); 77 78 VTableContext &getVTableContext() { return VTContext; } 79 80 /// \brief True if the VTable of this record must be emitted in the 81 /// translation unit. 82 bool ShouldEmitVTableInThisTU(const CXXRecordDecl *RD); 83 84 /// needsVTTParameter - Return whether the given global decl needs a VTT 85 /// parameter, which it does if it's a base constructor or destructor with 86 /// virtual bases. 87 static bool needsVTTParameter(GlobalDecl GD); 88 89 /// getSubVTTIndex - Return the index of the sub-VTT for the base class of the 90 /// given record decl. 91 uint64_t getSubVTTIndex(const CXXRecordDecl *RD, BaseSubobject Base); 92 93 /// getSecondaryVirtualPointerIndex - Return the index in the VTT where the 94 /// virtual pointer for the given subobject is located. 95 uint64_t getSecondaryVirtualPointerIndex(const CXXRecordDecl *RD, 96 BaseSubobject Base); 97 98 /// getAddressPoint - Get the address point of the given subobject in the 99 /// class decl. 100 uint64_t getAddressPoint(BaseSubobject Base, const CXXRecordDecl *RD); 101 102 /// GetAddrOfVTable - Get the address of the vtable for the given record decl. 103 llvm::GlobalVariable *GetAddrOfVTable(const CXXRecordDecl *RD); 104 105 /// EmitVTableDefinition - Emit the definition of the given vtable. 106 void EmitVTableDefinition(llvm::GlobalVariable *VTable, 107 llvm::GlobalVariable::LinkageTypes Linkage, 108 const CXXRecordDecl *RD); 109 110 /// GenerateConstructionVTable - Generate a construction vtable for the given 111 /// base subobject. 112 llvm::GlobalVariable * 113 GenerateConstructionVTable(const CXXRecordDecl *RD, const BaseSubobject &Base, 114 bool BaseIsVirtual, 115 llvm::GlobalVariable::LinkageTypes Linkage, 116 VTableAddressPointsMapTy& AddressPoints); 117 118 119 /// GetAddrOfVTable - Get the address of the VTT for the given record decl. 120 llvm::GlobalVariable *GetAddrOfVTT(const CXXRecordDecl *RD); 121 122 /// EmitVTTDefinition - Emit the definition of the given vtable. 123 void EmitVTTDefinition(llvm::GlobalVariable *VTT, 124 llvm::GlobalVariable::LinkageTypes Linkage, 125 const CXXRecordDecl *RD); 126 127 /// EmitThunks - Emit the associated thunks for the given global decl. 128 void EmitThunks(GlobalDecl GD); 129 130 /// GenerateClassData - Generate all the class data required to be generated 131 /// upon definition of a KeyFunction. This includes the vtable, the 132 /// rtti data structure and the VTT. 133 /// 134 /// \param Linkage - The desired linkage of the vtable, the RTTI and the VTT. 135 void GenerateClassData(llvm::GlobalVariable::LinkageTypes Linkage, 136 const CXXRecordDecl *RD); 137 }; 138 139 } // end namespace CodeGen 140 } // end namespace clang 141 #endif 142
